Device to be mounted on the front part of a motor vehicle

ABSTRACT

A device for a front-end component part of a motor vehicle, behind which a radar transmitter/receiver is fastened in such a way that the latter is not visible from in front. In winterish surroundings, ice and snow deposits may occur on the front component part, whereby the functionability of the radar sensor may be impaired. It is possible to remove and/or prevent these precipitation deposits on the front component part.

FIELD OF THE INVENTION

The present invention relates to a device for a front-end component partof a motor vehicle, behind which a radar transmitter/receiver isfastened in such a way that the latter is not visible from in front. Inwinterish surroundings, ice and snow deposits may occur on the frontcomponent, whereby the functionability of the radar sensor may beimpaired. According to the present invention, it is possible to removeand/or prevent these precipitation deposits on the front component.

BACKGROUND INFORMATION

German Patent Application No. DE 197 24 320 describes a method forproducing an heatable antenna lens. A heatable antenna lens is describedthat is made of a dielectric substance, which has inside of it an arrayof electrical conductors, the electrically conductive array not lying ina plane.

On page 263 ff, design and operation of headlight cleaning systems aredescribed from the book, “Automobile Electrical Systems, AutomobileElectronic Systems”, Vieweg-Verlag, 3rd edition, 1998. Such headlightcleaning systems have the objective of removing the dirt on the lensesof the main headlights. The embodiment variant of the high-pressurewashing systems described stands out in that it may be used both forglass lenses and for plastic lenses. The cleaning effect is determinedmainly by the cleaning impulse of the water drops. As the importantvariables of the cleaning impulses, the distance between nozzle andlens, the size, the angle of incidence and the speed of incidence of thewater drops, as well as the quantity of the water are named.

SUMMARY OF THE INVENTION

An essence of the present invention is a device for a front cover partof a motor vehicle. This device is advantageously in in a position toremove and/or prevent precipitation deposits on front cover parts of amotor vehicle, in liquid or solid form.

It is particularly advantageous that, as a front cover part, a bumper, aspoiler, a radiator cover, the engine hood or an illuminating device isused.

Advantageously, the precipitation deposits are removed and/or preventedby a direct or an indirect supply of heat.

In a particularly advantageous manner, the direct supply of heat isperformed with the aid of heating wires which are built into the frontcover part.

By electrically resistive heating up of these heating wires, at leastthe region of the front cover part, which is penetrated by theelectromagnetic waves of a radar sensor, is heated, wherebyprecipitation deposits in the form of snow or ice are removed and/orprevented.

An indirect supply of heat is advantageously given by an air or liquidcurrent of the engine waste heat that is transported to the region ofthe front part which is penetrated by the electromagnetic waves of aradar sensor. A great advantage of this variant of the embodiment isthat the waste engine heat, which is of necessity produced in thevehicle, but is lost, is used to de-ice the front part. The transport ofthe engine waste heat, from the engine region to the front part, takesplace through an air channel, in that, advantageously, a fan having adrive provided in the air channel aspirates the air heated by the engineand conducts it in a controlled manner to the region of the front partthat is to be de-iced, or rather to be protected from icing up.Likewise, the indirect heating of the front component part may takeplace with the aid of a liquid flow. In this connection, it isconceivable that a water-filled hose system removes the engine heat andpasses it on in a controlled manner to the front component part. Forthis, advantageously, the cooling liquid circulation of the engine isused, in that a part of the heated cooling liquid is not taken directlyto the radiator, but is first conducted past the front component part.

It is especially advantageous to select the surface of the frontcomponent part in the region that is penetrated by electromagnetic wavesof the radar sensor in such a way that precipitation deposits areprevented from the start.

This is done advantageously by using a material that has a sufficientlygreat contact angle or wetting angle, when in wetting equilibrium, sothat water is repelled. This material may either be only applied to thesurface of the front component part in a thin layer, or the frontcomponent part may partially or solidly be made of this material.

It is particularly advantageous if a substance such aspolytetrafluoroethylene or a perfluorinated silane is used for this.

In addition, it is advantageous if the precipitation deposits on thefront component part are removed and/or prevented by using an antifreezeliquid. This happens advantageously by providing spray nozzles in thesurroundings of the region of the front component part, which ispenetrated by electromagnetic waves of the radar sensor. For thispurpose, the spray nozzles are connected, with the aid of a hose, to theoutput side of a pump, which in turn is connected to a storagecontainer, and whereby an antifreeze liquid is sprayed onto the frontcomponent part.

As the storage container for the antifreeze, one may advantageously usethe storage container that is already present for the windshield washingsystem.

In addition, combinations of the devices shown here are alsoconceivable, so that a precipitation deposit in liquid or solid form maytake place (be removed and/or prevented) in the region of a front coverpart, which is penetrated by electromagnetic radiation of a radarsensor, by the cooperation of several of the variants presented here.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a first exemplary embodiment of a device according to thepresent invention.

FIG. 2 shows a second exemplary embodiment of a device according to thepresent invention.

FIG. 3 shows a third exemplary embodiment of a device according to thepresent invention.

FIG. 4 shows a fourth exemplary embodiment of a device according to thepresent invention.

DETAILED DESCRIPTION

FIG. 1 shows a motor vehicle 1 in a front view. Front component partsmay also be recognized. Going into details, these are lighting devices7, a radiator cover 8, front bumper 5 and a front spoiler 6. Inaddition, a radar sensor 2, for transmitting and receiving microwaveradiation is drawn in. This radar sensor is built in, in this exemplaryembodiment, behind the bumper and the front spoiler. According to thepresent invention, it is, however, also possible to install such asensor in illuminating device 7 or behind radiator grille 8. It wouldalso be conceivable to integrate the radar sensor into the engine hood.Moreover, an electrical heating wire 3 is provided, which is insertedinto one or more front component parts 5, 6. This electrical heatingwire 3 has two connecting points 4 a, 4 b to which a control orregulating device may be connected, in order to operate the heating wirein a suitable manner. If a current is flowing through electrical heatingwire 3, the front component part, into which the electrical heating wireis built in, is heated. The heating of front component parts 5,6,7,8 isto be designed in such a way, in this context, that deposits ofprecipitations, especially in the form of snow or ice, is prevented, andalready existing deposits of precipitation deposits may be removed. Inthis way, the front component part may be kept free from snow and iceeven in winterish surroundings, whereby functional impairment of theradar sensor is avoided.

FIG. 2 shows a motor vehicle 1 in a side view. This drawing shows asecond exemplary embodiment of the device according to the presentinvention. The side view of vehicle 1 is limited to the front part ofthe vehicle, the left front fender being shown. In this view too,various front component parts, behind which radar sensor 2 may bepositioned, are shown. Thus, front bumper 5, forward front spoiler 6 aswell as a front illuminating unit 7 are shown in detail. Furthermore,radiator cover 8 should be mentioned, which cannot be recognized in thisrepresentation. As a part of vehicle 1, engine 10 is drawn in, which isin particular developed as an internal combustion engine. The waste heatwhich this driving device generates, is aspirated with the aid of an airline channel 11 in the engine compartment, and transported further by afan having drive 12. This air duct channel 11 is made in such a way thatits air discharge opening directs a flow towards front cover part5,6,7,8. In this context, the front cover part has the hot engine wasteheat flowing at it in such a way that, in particular, the region,through which the electromagnetic radiation of radar sensor 2penetrates, is heated up. Because of the heating, especially of theregion of the front component part which is penetrated by the radarradiation, it is possible to remove precipitation deposits in the formof snow or ice, and to prevent a new deposit.

FIG. 3 shows an additional variant of an embodiment of the presentinvention. One may see again a motor vehicle 1 in a front view. At thefront end this has so-called front component parts, especially in theform of a bumper 5, of a front spoiler 6, in the form of twosymmetrically situated illuminating devices 7 as well as a radiatorgrille 8. In addition, at the front end of vehicle 1, a radar sensor 2is provided, which transmits and receives radar radiation, and which mayparticularly be used for adaptive cruise control. For esthetic reasons,the radar sensor is mounted behind one or several of the front componentparts 5,6,7,8 named. In this context, it should be mentioned that thefront component parts 5,6,7,8 must be made of a material that ispermeable to electromagnetic waves and does not absorb them. Accordingto the present invention, radar device 2, which in this example issituated behind front bumper 5 and front spoiler 6, can also be situatedbehind another front component part, such as radiator cover 8, one oftwo illuminating devices 7 or the engine hood. In the exemplaryembodiment shown here, the front component part, or rather frontcomponent parts 5,6, behind which radar sensor 2 is hidden away, arecoated with a special surface. This special surface is applied in atleast the region of the front component part which is penetrated by theelectromagnetic radiation of radar sensor 2. This special surface, whichis applied to front component part 5,6,7,8, in the exemplary embodimentshown in FIG. 3, has a broken line 9 around it as an edge. Of course,this special surface may also be applied on a greater region or over theentire front component part. Advantageously, in the case of this specialsurface, one may use a surface material which has the property ofrepelling water or substances similar to water, in that this surfacematerial forms a sufficiently great contact angle or wetting angle. As alarge contact angle, in this case, one would understand an angle of atleast 90°. The contact angle or the wetting angle is the angle thatforms during wetting equilibrium at the edge of a drop on a solidsurface between the drop surface and the solid surface. Furthermore,this material should make it possible to be applied to plastics in asimple and cost-effective way, especially on plastics which are used forbody elements in automobile construction. As surface materials,particularly substances like perfluorinated silanes orpolytetrafluoroethylene (Teflon) are suitable.

FIG. 4 shows a fourth exemplary embodiment of the device according tothe present invention. Here too, as in FIG. 2, the front side view of amotor vehicle 1 is shown. One may recognize here the front componentparts, such as front bumper 5, front spoiler 6, front illuminatingdevices 7, radiator grille 8, as well as the engine hood that is notvisible in this representation. In this exemplary embodiment too, radarsensor 2 is mounted behind front bumper 5 and front spoiler 6. However,it is also conceivable to position this radar sensor 2 behind adifferent front cover part, such as the engine hood, an illuminatingdevice 7 or radiator grille 8. The specific embodiment shown forremoving and/or preventing precipitation deposits at the region of thefront component part, which is penetrated by the radar radiation ofradar sensor 2, takes place with the aid of an antifreeze. For thispurpose, storage tank 13 is sketched in sketch form, and it includes afeed pump. This feed pump takes the antifreeze fluid from storage tank13 and conducts it through a supply line 14 to spray nozzle 15. Thisspray nozzle is advantageously fastened to the front bumper, and isaligned in such a way that the region of the front cover part, that ispenetrated by radar radiation, is able to be wetted by the sprayedsubstance. In the spraying system shown, advantageously a high-pressuresystem is involved, which applies the antifreeze to the front cover partat a high spraying pressure. Because of the property of the antifreezethat it lowers the melting point, it is possible to de-ice the partswetted by the antifreeze, and at the same time to remove solid depositsusing the effect of the jets. In an advantageous manner, the antifreeze,which may also be made up of a mixture of antifreeze and water, is takenfrom the storage tank for the headlight washing system and from thestorage tank for the window washing system.

In addition, combinations of the devices shown here are alsoconceivable, so that a precipitation deposit in liquid or solid form maytake place in the region of a front cover part, which is penetrated byelectromagnetic radiation of a radar sensor, by the cooperation ofseveral of the variants presented here.

1. A device for at least one front component part of a motor vehiclecomprising: an arrangement for at least one of removing and preventingprecipitation deposits in at least one of solid and liquid form in anarea of a surface of the front component part; a radar sensor foradaptive cruise control, wherein the radar sensor is positioned behindthe at least one front component part, at least one portion of the frontcomponent part being penetrated by electromagnetic waves of the radarsensor; and at least one electrical heating wire built into the at leastone portion of the front component part penetrated by electromagneticwaves of the radar sensor, wherein the at least one electrical heatingwire provides a direct supply of heat; wherein the at least one frontcomponent part includes at least one of a bumper, a spoiler, a radiatorgrille, and an illuminating device, and wherein the precipitationdeposits are at least one of removed and prevented by the direct supplyof heat from the at least one electrical heating wire.
 2. The deviceaccording to claim 1, wherein the front component part includes a frontcover element.